During this period, the work has been concerned with obtaining whole-cell recordings from depolarizing bipolar cells in a consistent fashion. This usually requires dipping briefly the electrode tips in a protamine solution, a treatment that fails when phosphonucleotides are added to the electrode solution because they react with protamine and cancel its effect. In spite of numerous attempts to find alternative methods, the protamine treatment of the electrode remains the only effective one. Therefore, its use will be continued but provisions have been made to add of recording has been established.